With walking plaster casts, the plaster cast has to be protected from a direct contact with the ground since otherwise a fracture and a disintegration of at least part of the plastered mass would rapidly occur. The technique known hitherto consists in incorporating into the plaster mass which is below the foot, wads or pads protruding below the plaster cast and called "walking heel-pieces". Said walking heel-pieces comprise a body of generally cylindrical shape the upper end of which is formed with flexible side ears or bands imbedded when laying the plaster cast inside the layers of plastered bands. With such walking heel-pieces, the body weight is transferred to the ground via the section of the cylindrical body, and due to the small thickness of the plastered mass interposed between the foot and the upper surface of the heel-piece on the one hand, and to the residual flexibility resulting therefrom of the interposed plastered layer on the other hand, the result is a notable compression of the area of the sole of the foot situated above the heel-piece, which causes a feeling of discomfort and even of pain. Moreover, when the patient is in a seated position with his leg stretched, the heel-piece is no longer in contact with the ground and the portion of the plaster cast which is behind the heel is in contact with the ground.